Resistance to politically correct attempts to expunge Christianity from our culture — the conversion of Christmas into “winterval” is symptomatic — should be encouraged, but one can push the defence of Christianity farther by imagining what Western society would be like without it.

Christianity was responsible for the great “revaluation of values” that drove Friedrich Nietzsche mad in his quest to liberate a higher man from the collective cringe of the “herd” towards a transcendent god. A figure who suffered the fate of common criminals was at the centre of Christianity’s redemptive drama; its sacred texts were peopled by lowly characters rather than the merely powerful.

It was and is a highly cosmopolitan and egalitarian religion, recognising neither Greek nor Jew, bond nor free. That, in addition to such novel ideals as charity, compassion and peace, and the status attached to women, differentiated Christians from a surrounding society based on cruelty, hedonism and organised slavery. Imagine yourself as a slave, rather than Caesar or Cicero, in Ancient Rome, and you’ll get the hang of it.

Through its marriage of convenience with Rome, Christianity established that rulers were responsible for their conduct in an afterlife. From the redoubtable Ambrose, archbishop of Milan, who tamed the emperor Theodosius, to Pope Gregory VII, who forced emperor Henry IV to Canossa, the Church defined a sphere that was separate from the State. This is one of the distant ancestors of modern “civil society”. During the long night of totalitarianism, when rulers reverted to being mortal gods, the churches defended that space.

The early Christian churches performed many of the functions that we nowadays associate with the State, through provision of charity, infirmaries, and above all, scholarship and education. Its own structures absorbed those of the Empire, with the difference that the Church reconciled hierarchy with meritocracy just as its culture encompassed the intellectual heights of theology as well as low-level pagan superstition. Thanks to the Church, the barbarians gained written law and a sense of historic purpose.

Christianity, or more particularly the bishops of Rome, determined how people thought of time, whether through the calculation of Easter or, from AD525, how they divided human history. Work, especially agricultural labour, was positively revalued, with religious orders playing a vital role in reclaiming bleak regions for human habitation. Just as early Christianity had eradicated men slaying each other in arenas, so the medieval Church endeavoured to create oases of peace within endemically violent societies.

Modern Western man still likes to describe himself as vaguely “spiritual”, the default position that reflects dim awareness of something lost. But who would say “unspiritual” or “grossly materialistic”? For the evidence of what a society without Christianity would be like lies around us. It is Aladdin’s cave courtesy of Amex and Mastercard.

The stressed-out workaholic is a slave to work and the material things labour buys. Mindless hedonism, which Christianity once successfully eradicated or sublimated, is endemic on TV. As audiences, rather than commissioning editors, grow bored with images of sexual deviancy, how long will it be before this is replaced by the equivalent of the Roman arena? “Good idea,” thinks a TV Tristram! Dan Brown’s book, consisting of bizarre conspiracy theories, is the best-selling bible of credulous housewives.

Scruffy Irish pop stars and smart chefs are the new moral arbitors, while aspiring politicians vie to demonstrate their knowledge of Radiohead or Franz Ferdinand rather than two millennia of European high culture. Education has ceased to be concerned with cultural enrichment, as it awards every dullard a coconut, just as scholarship has to battle its way through a business culture of outcomes and outputs. Welfare, dispensed by a State that has obliterated any sense of individual responsibility, has created new forms of appetency and an angry culture of perpetually frustrated rights. Scientists try to cut every corner regarding what Christianity established as the sanctity of human life, or they proselytise atheism with an evangelical fervour.

People with little or no historical knowledge of Christianity are allowed to caricature it as divisive, fraudulent or oppressive. When did they last visit the Vendée, Auschwitz or Vorkuta to see secular rationality in all its glory? Everywhere is evidence of colossal social breakdown, whether dysfunctional families or the drunken degradation of chavscum.co.uk, which reflects a reality on our streets. While governments ponder such things as the fires in Paris’s banlieus, a number of thinkers, including Régis Debray, the former Marxist guru, or Umberto Eco, the novelist, have begun to rediscover the social utility of religion.

As Debray argues, the opium of the masses was in fact the vitamin supplement of the poor, whether in terms of providing a code of values or practical help and a sense of moral worth to even the most disadvantaged. Perhaps Dr Sentamu should emphasise the positive legacy of Christianity, leaving the Government to tell immigrants how to open a bank account, their dismal understanding of what this society stands for.

Michael Burleigh is the author of Earthly Powers. His More4 documentary Dark Enlightenment will be broadcast in the new year.

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